Dear FLUKA users,
I have a confused problem about the contribution of different particles to the detector signal when the detector is placed in a mixed filed. The mixed field is mainly consist of gamma, neutron and electron. The sketch is shown in the attachment. I think I know how the signal is to be generated. When the gamma enter the detector sensitive zone, it will produce electrons by photoelectric effect, compton effect and pair effect, then generated electrons contine a further ionization. Similar process is applicable to neutrons except that neutrons are via some reactions. But electrons in the mixed field has a rather low energy that they cannot penetrate the detector shell.
Using the USRBIN and AUXSCORE cards, I evaluate the signal by the energy deposition methods and the contribution of different particles outside the detector, i.e., the surrounding radiation field. However, the computational results are strange, gamma, neutron, and electron all have energy deposition, the most contribution is from electrons. I think the contribution of electrons is from the ionization process of the generated electrons in the detector by gamma and neutron incident, but not from the outside electrons. I have two doubts as follows:
1. If all the energy deposition is from electron ionization(
http://www.fluka.org/web_archive/earchive/new-fluka-discuss/7931.html ), what is the small deposition value given by gamma and neutron? Is it the Non-ionising energy losses (NIEL)?
2. How to evaluate the signal contribution of particles outside the detector? If I attribute the generated electrons causing by gamma entering in the detector sensitive zone to the gamma contribution (assuming it get a value A), and so do it for neutron (assuming it get a value B). A/B may be the contribution ratio of gamma to neutron. But do you know how to finish it? AUXSCORE card as a filter fails to finish since it scores the energy deposition inside the detector and always get the boring results that the maximum contribution is always from electrons. Whether or not the solution is using the so called "two step methods"?
Any help is appreciated.
T. Yang
CAS
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Received on Thu Nov 24 2016 - 23:17:27 CET
